This invention relates to a method of production of vibration absorbing metallic material which can achieve superb effects in vibration damping when used in fabricating equipment including industrial machinery and household appliances which might raise a problem with regard to vibration and noise.
Heretofore, a Mn-Cu alloy (Japanese Laying-Open of Patent application No. 50-20913), a Ti-Ni alloy, a Fe-Cr-Al alloy (Japanese Laying-Open of Patent application No. 50-71512), Mg, a Mg-Zr alloy and graphite flake cast iron (Japanese Laying-Open Patent application No. 51-54820) have been known as metallic materials having the property of absorbing vibration. Besides these materials, vibration absorbing material in laminate form consisting of a plate made from a synthetic resinous material and metallic raw materials sandwiching the resin plate therebetween is known as shown in Japanese Laying-Open of Patent application No. 51-26676.
However, of all the aforementioned materials, the materials other than cast iron and Mg materials are not widely in use due to the fact that they are generally quite expensive. Aside from being expensive, the Mn-Cu alloy raises problems in regard to temperature characteristics and changes in quality which occur with time. In the Fe-Cr-Al alloy, a problem arises in regard to its workability.
Cast iron and Mg materials are free from the aforesaid disadvantages. However, when attempts are made to improve the vibration damping ability of these materials, it brings the defect of strength of these materials being reduced. Thus a problem is encountered in putting these materials to practical use. Also, the aforesaid material in laminate from raises problems in regard to its ability to damp vibration, namely its temperature characteristics and its workability.